Want to make your apps more Apple-like? Apple has just made its app design principles available in a free ebook (released, annoyingly for us Kindle owners, via iBooks).
The "iOS Human Interface Guidelines" are also available online as part of Apple's developer portal, but having them in book form could make for easier browsing. As our sibling site Gizmodo points out, the guidelines spread beyond design to other features with recommendations like this:
Don't tell people to reboot or restart after installing your app. Restarting takes time and can make your app seem unreliable and hard to use.
iOS Human Interface Guidelines [iTunes]